Doom: Gaia Theory
by Hawki
Summary: D3 Oneshot: Mars was a dead world long before Hell invaded. Funny how Earth was now dying, prompting colonization of the red planet...and repeating the same mistakes the ancient Martian civilization had.


**Gaia Theory**

Mars was called the red planet.

Looking at it through the wall of transparisteel that covered a whole section of her office, Captain Rachel Gainsborough reflected that it looked more orange from up here. Even after the incident on the surface four days ago, after all the blood that had coated the walls of Mars City, Mars still didn't look red. Mars looked the same as it always had through the entirety of human existence. Dry. Barren. Lifeless. Officially, the only life it had known was a few thousand souls who had dwelt in a colony colloquially referred to as Mars City. Unofficially, and known only to a select few, it had been home to an ancient race believed to have fled to Earth to escape some kind of cataclysm, arriving in the same period where modern humans were starting to come into their own. It was a point of arrival whose implications weren't lost on her, and she doubted the archaeologists the UAC employed either.

Course most of those archaeologists were dead now. Least all the ones who'd been on Mars. Four days ago, the "incident" had begun. Three days ago, the "incident" had ended. Two days ago, the fleet had arrived per a distress call sent by Master Sergeant Thomas Kelly. One day ago, a call had been sent to Earth that everyone on Mars was dead save a single marine, who after what little he'd told them, had indicated that he was either mad, or Mars City had suffered something much worse than the cover story the UAC and Space Marine Corps were going with.

"Captain?"

A cover story that had to be extended to the fleet as well. How that was going to work, she didn't know. Either way, she turned away from the oranges of Mars, and to the blues of the uniform of Commander Brown.

"Commander," she said.

He held up a data chip. "Something you might want to see."

She raised an eyebrow. "Might?"

He walked past her to the terminal at her desk. "Well, only saying 'might,' since neither of us are of a paygrade meant to see this. So we 'might' be getting ourselves in trouble. But we 'might' be in a position to better understand what the hell happened on Mars, even if Admiral Liu is keeping it under wraps. So we 'might' be better put at ease."

"Or we 'might' be court martialled and sent back to Earth."

What little colour there was left in Brown's face, she reflected. Sent back to Earth. That was almost as bad as being sent to Mars. There were a few perks to spending most of your time in space, and among them was that you didn't need to worry about food and water shortages, or being murdered as dogs ate each other to survive. Giving her XO a small smile, she took the data chip out of his hands and plugged it into the terminal herself.

"Don't worry," she said. "This is on me. If I take the fall, I won't grab hold of your arm."

"Duly noted ma'am," Brown murmured. "But I'm left to ask why you're taking the risk at all."

She looked up at him from the terminal. "Getting cold feet?"

"No. I want to know too. Preferably through means that don't involve a data thief."

Rachel opened the first of the files and hit 'play.' "I'll keep that in mind," she murmured. She activated the terminal's projector so that the playback would be displayed on one of her office walls. It showed footage dated 15/11/45, in Delta Labs. Given the number of scientists and engineers milling about by some kind of teleportation portal, she deduced that it was before "the incident."

_But I'm left to ask why you're taking the risk at all._

Brown's words echoed in her mind. Why take the risk indeed? She knew the answer, at least in part – whatever story the UAC would run with, it was a story that would bear little resemblance to the truth. And even as captain of the _Edmonds_, a mid-sized cruiser within the fleet, she'd only get slightly more of the truth. And given what truths she already knew about Mars, Earth, and the UAC…

She wanted at least some truth. No matter how horrible it was. So when the portal began to shift, when the lights began to flicker on and off, when Delta Labs began to shake as if some kind of tectonic movement was occurring, she kept watching. Even as…

"The hell?" Brown whispered.

Even as what looked like floating skulls came pouring out. Even as a ten foot tall…_thing_, lumbered out of the portal, instantly grabbing an engineer and tearing the man in half like a child might snap a twig. Even as strange creatures appeared in bursts of light, either tearing into the staff with their claws and teeth, or conjuring balls of fire to throw at their prey. Even as the feed went blank.

Brown said nothing. Rachel said nothing. She remained silent as she walked back to the terminal and opened the next file, but not before setting it to auto-play. She'd seen things on Earth and even Luna that had churned her stomach, sometimes bringing that churning out of her mouth. Whatever the hell had happened on Mars, she could stomach this as well.

Or so she thought. Because what followed was a series of security cam footage that had been cobbled together – not by Brown, he'd just used a data thief – but by someone higher ranked, likely to send to the boys and girls back on Earth. The footage progressed, the time stamp always slightly increasing. Some lasted a few minutes, some only seconds. But in it, Rachel could see the story of Mars City. Something happened in Delta. Something that brought…_aliens_, for lack of a better word. The camera footage showed them killing the staff. It showed the assigned marines killing the creatures before eventually being overwhelmed. Before long, all that was left were the empty corridors of Mars City, with a few survivours, a few of the aliens, and numerous shambling corpses. Zombies, Rachel reflected. Zombies that had the ability to carry guns and at times shoot them, but zombies all the same. The kind of stuff that had been in vogue in the last two centuries.

Eventually the camera feed shifted to that of the marines the fleet had brought with it. Moving through the corridors, dispatching what few creatures remained – zombies, and those clawed, demon-like aliens. Both in the corridors of Mars City, and even in the ruins of the dig sites. In the shadows of the ancient Martian civilization, the marines cautiously made their way through, dispatching the aliens and small spider creatures as well. The last camera feed, dated from only one day ago, showed them arriving in a giant cavern. In the centre was what looked like newly formed rock – like a lava flow, if lava made a perfect circle upon cooling.

"Holy shit," Brown whispered.

It was the first word he'd said in an hour, and Rachel couldn't blame him. Because as strange as the rock in the centre appeared, what was even stranger was the giant…_thing _lying on the ground beside it. It had horns. It had hoofs. It had a giant cannon for an arm, and it was lying on the ground, dead – it hadn't even started to decompose, likely due to the lack of microbes in the Martian atmosphere. The camera feed ended with one of the marines giving its head a kick with his boot, before the feed cut out.

A silence descended upon Rachel's office. Both she and Brown looked at each other slowly. As if playing chicken to see who would speak first.

"So…"

Brown lost it.

"Is this where I say that-"

"You don't say anything," Rachel murmured. "Neither of us do."

"As in, to anyone outside this room? Or we don't say anything, period?"

Rachel didn't say anything. She didn't have the answer. She didn't even bother to stop Brown as he removed the data chip from her terminal. She watched as he cradled it in his hand, as if he was holding the Holy Grail or something.

"You know," he murmured, "it's pretty much common consensus that Mars became a dead world four billion years ago." He glanced out the window, towards the planet below as if to make his point. "Were the Martians hiding underground during that time, or…"

"Or you think maybe those other aliens had something to do with it?" Rachel asked.

"I will say it entered my mind some way along the past hour."

She didn't say anything. Partly because it had entered her mind as well, and she didn't want to give voice to it. The timeframes didn't match up, granted – Mars had died four billion years ago. Martian civilization was meant to have collapsed 100,000 years ago. But maybe their battle with those creatures had lasted that long. But whatever the truth of that matter, what did it mean for Earth? Mars was dead. Earth was dying. It was why the UAC was not only investing so much in terraforming technology, but also teleportation technology. Because not only did Mars have to be made habitable, but there was no way to get everyone off Earth without something more efficient than spaceships.

She couldn't tell Brown that. She couldn't tell anyone that. Colonization of Mars was still officially to serve the interests of Earth, not be an end in of itself. And with this shit having gone down…

"You're dismissed Brown."

He gave her a nod and headed out. Not seeing as she got to her feet to look back down on Mars. Upon the sands, upon the dried out valleys, upon the frozen water up at the north pole. The last signs of a planet that had once been much less inimical towards life.

_Is this how it started? _She wondered. _Your planet dies, you develop teleportation tech to get to Earth, and things go bad for you? Like they did for us?_

She didn't know. But she knew Mars was dead either way.

Just like Earth would be.


End file.
